Brown explains that the trend is not unlike contouring your face with makeup. "Hair contouring is using dark and light colors to help soften or accentuate different features on your face," she said. It also has the added bonus of adding dimension to your hair, which can make it look fuller.
Similar to makeup, how you choose to contour will depend on your face shape. If you'd like to make a longer face seem rounder, Brown suggests adding brighter pieces toward the ends of the hair. Have a round face? Brown says that highlights paired with darker pieces framing your face will make it look longer.
Brown also suggests thinking about what you want to hide and what you'd like to accentuate. "Brighter and lighter tones help soften imperfections where [as] darker tones highlight it more," she said. "Think of a picture frame; when you want to see every detail you frame it with black while it's the opposite when you frame it in white."
While this may only be the beginning of products labeled as contouring sprays, you can also achieve the same effect with other spray-on color products. Check out a few options, ahead.